Hypodematium
Content
Distribution
Asia-Tropical, East Asia present, Tropical Africa present
C. 12 species in East Asia, two in Malesia. H. crenatum widespread, also in tropical Africa.
Anatomy
The vascular cylinder (after Nayar & Baipai 1970) is distinctive and has a broad, undivided ventral half and a dissected dorsal half, looking like that of Lomariopsidaceae; in adult rhizomes there are generally three irregular rows of leaf gaps dissecting the dorsal half of the stelar cylinder, the leaf gaps are clearly arranged in a spiral around the vascular cylinder, with a larger distance between successive gaps on the ventral side; the leaf gaps are large and spindle shaped and dissect the dorsal half of the stele into narrow, ribbon-like strands; leaf traces are paired, ribbon-like strands and the leaf gap extends conspicuously on the adaxial as well as on the abaxial side of them.